1. Field of the Invention
This invention relates to the ability to simulate a metallic pair of conductors, such as used on telephone and other communication lines, as to provide a resistive value necessary to activate line amplifiers attached to said metallic pairs.
2. Description of the Prior Art
One of the common types of metallic pair communication problems is lack of sufficient underlying electrical current to provide adequate customer service in the communications industry. This is because as the length of metallic pairs increases so does its resistance to current flow. The method of restoring the minimum underlying current necessary for adequate communication service is to attach a line current amplifier at the source of the metallic pair. This line amplifier attached in series with the metallic pair at its source is activated when it senses a minimum resistance short across the pair such as that generated by a telephone instrument's hand set being lifted a distance away from the source of the metallic pair.
When insufficient current on the amplified metallic pair is detected, a technician must travel away from the source of the metallic pair, commonly known as a Telephone Exchange, to a distance necessary to activate the turn on feature of the line amplifier. Usually, this is 32,260 feet of 22 gauge metallic pair wires away from the source, Exchange, which is equivalent to approximately 1000 OHMS of resistance measured at 70 degrees Fahrenheit, this being the minimum resistance necessary on the metallic pairs to activate a line amplifier. If the technician determines no underlying current increase is present on the metallic pair at the distance, he must return to the source, Exchange, and put a new line amplifier in series with the suspect metallic pair in place of the faulty unit. After this is accomplished, the technician must travel once more to the minimum distance location to test for the line amplifier's operation. Clearly, this operation of adding, changing, metallic pair line amplifiers can be time consuming and costly due to the necessary travel between the source and the resistive distance necessary to activate the amplifier.
The metallic telephone pair of wires is tested by a technician at the distant end or at an intermediate point of minimum resistance value length required, by inserting a telephone test set or a standard milliampere meter across the pair and taking a measurement reading. He then compares this reading against his company's acceptable value. Having done this, the technician determines if the current reading is acceptable or not which at this point, if not, he must return to the intermediate minimum resistance points to find where the current is lost up to and including the source, Exchange. This is the present procedure for fault locating which is both time consuming and costly. At times, this is minimized when another technician is at the source to work with the outside technician. More often, with the change in technology, exchanges are not manned and therefore the technician must travel back and forth repeatedly to fault locate.